Storm Intensity in Pacific Northwest Marine and Coastal Systems

Warm air can hold more water vapor and accelerate the water cycle. This raises the potential for increased storminess and increased intensity of storms. Projecting where increased storminess will occur is an active field of research with high regional variation throughout the world. It is unknown at this time whether the number and severity of storms will change in the Pacific Northwest and the Pacific Islands as climate change progresses. One observational study notes that the global water cycle has sped up roughly 4% while the surface warmed 0.5°C in the past 50 years.

If storm intensity does increase in the Pacific Northwest potential effects to coasts include erosion and other damages caused by coastal water storm surges as well as even bigger mega-floods that sporadically visit the Pacific Northwest coast (more about mega-floods). Other research shows that a seemingly low increases in sea level will have significant impacts when storm surges occur because these surges magnify sea level rise five times and increase the frequency of historic flood events exponentially.

The El Niño Southern Oscillation also affects storminess, annual wave conditions and monthly mean water levels that raise tidal elevations, storm surge and flooding risk. In Oregon and Washington, El Nino years have been found to increase deep-water wave heights, runup levels on beaches and elevated tides as compared to normal or La Nina years.

For more information or a refresher on El Niño check out this National Geographic video explaining the origins of the El Niño Southern Oscillation using animations and shows the impacts on humans, wildlife and habitat, particularly in the United States: